James mackintire



. NITED STATES PATENT FFICE.

JAMES MAOKINTIRE, or SHEFFIELD, ENGLAND.

@OMPOSITION' FOR USE IN THE MANUFACTURE OF STEEL.

SPECIFICATION forming part of Letters Patent Nb. 449,547, dated March 31, 1891. Application filed December 6, 1890. Serial No. 373,313- (No specimens.) Patented in England January 6, 1890, N0. 213.

T0 aZZ whom, it may concern:

Be it known that I, JAMES MACKINTIRE, engineer, of 27 Victoria Road, Broomhall Park, Sheffield, in the county of York, England, a citizen of the United States of America, have invented certain new and useful Compounds for Use in the Manufacture of Steel and Iron, (for which I have obtained Letters Patent in Great Britain, No. 213, dated January 6, 1890,) of which the following is a specification.

The object of this invention is the manufacture and production at a small cost of steel of a high class and quality out of various grades of iron, and, where necessary, out of the more common and less costly grades of iron, by means of the addition of the combination of ingredients hereinafter named, and which can be used either in the crucible, Bessemer-converter, Siemens-Martin, open-hearth process, or with any other method of making steel in use at the present time.

The ingredients hereinafter named can be used either directly in form of a powder, paste, or cake, as preferred, or as found to be most suitable to the metal operated upon, or they may be combined with a small charge of iron or steel, and such combination when molten can be run into molds and used as an alloy in a manner analogous to that employed when spiegeleisen or other alloys are used in the manufacture of steel and as hereinafter more fully described.

At the present time it has not been found possible to produce with certainty a highclass steel possessing a very high tensile strength and at the same time retaining sufficient elongation to preserve the toughness necessary to satisfy the requirements of engineers and manufacturers. Hitherto steel of the greatest tensile strength has often been found to be exceedingly brittle, and thus unfit for use. Again, when much elongation is required this quality has usually been obtainable at the expense of a considerable reduction in the tensile strength of the metal.

An essential feature of this invention is that by it steel can ,be made having a very high tensile strength and at the same time retaining a well-defined elongation and area of red notion, as well as possessing a special character that permits of its being readily manufactured and worked in a perfectly sound and merchantable condition, being free from flaws and scams, or cracks or cells, or what are sometimes called roaks, which are the common defects in manufactured steel of the higher grades, besides showing an evenness not to be found in any other steel.

By varying the proportions of the ingredients as used by me either in the powder, cake, or alloy, according to the requirements in any given case, steel of all kinds and for all purposes c'an be manufactured which will be found to be of great strength, ductility, and endurance, and also easy to forge, and which can be tempered by any of the known methods for the hardest service.

In the conversion of agiven weight of iron into steel by my process I proceed as follows, taking the quantities as examples, dealing, say, with a proportion of one hundred-weight of iron: First, I use of carbonate of calcium about ninety eight and one -half per cent, mixed with phosphate of calcium about one and one-half per cent, and of this'I take seven ounces; second, I use of black oxide of manganese, say, about five ounces; third,l use of tannic acid or tannin about half an ounce, and well combine samet'. e., Nos. 1, 2, and 3 together; fourth, I take of vegetable soot about six ounces and of animal charcoal or bone-black about two ounces and mix the same well together; fifth, I then take of tar two ounces and from two to three ounces of hot water, and when well mixed I add N o. 4 to it, and then the mixture of Nos. 1, 2, and 3, and by sufficient tritu ration I form the same into a compact cake.

The cake made as above is suitable for treating one hundred-weight of iron, and when operating in a crucible capable of containing, say, fifty-six pounds of iron a suitable proportion of the cake is introduced, either with the charge of metal in a cold state or when it is partially molten.

The ingredients Nos. 1, 2, 3, anda can be used together in a dry condition, and this combination produces an excellent effect on the steel; but when these are combined with the ingredients No. 5 and then baked the re suit is better. Results, however, show that the ingredients as first described, mixed together as before stated and left in the pasty condition, may be advantageously used, as it prevents the formation of what are called roaks.

The proportions used of each ingredient vary slightly, according to the materials treated and the nature of the metal reqniredi. a, hard or soft steel.

In using the process in the Bessemer converter or other similar converters or in the open hearths or paddling-furnaces, the total weight of the combined ingredients will be less or more in proportion to the charge of metal than that used for the crucible, according to the time taken in these processes, respectively, for the ingredients to become thoroughly amalgamated with the molten metal.

In practice I have found that the ingredients employed by me, as above indicated, work more evenly and reliably when introduced in the form of an alloy, as above mentioned, this being specially so in the case of the Bessemer converter.

I11 making this alloy I proceed as follows, using the same ingredients as before mentioned: In an ordinary steel crucible I place about forty pounds of pig-iron of any kind, but preferably hematite, and melt same to a pasty condition. To this I then add my said ingredients, mixed and treated as before mentioned in the case of the powder or cake, but in the following quantities: first, of the mixture of carbonate of calcium and phos-,

phate of calcium in the before-named proportions about one and three-fourths pound; second, black oxide of manganese about one and three-fourths pound; third, tannic acid or tannin about one and one-fourth ounce; fourth, soot one-half pound, animal charcoal one-fourth pound, about threefourths of a pound; fifth, tar one ounce, mixed with suflicicnt hot water to make a paste about one ounce. Nos. 1, 2, 3, L, and 5 are mixed and form a paste, which is added to the forty pounds previously placed in the crucible, and in addition I place about twenty-six pounds more of the pig-iron and melt the whole together, and when the charge is properly melted I teem and run the contents as required into molds.

I find that the above proportions work well when hematite is used, and that they may also be advantageously used with iron of other qualities in cases where it may be found convenient to use other kinds of iron. As experience in carrying out my process will readily guide the operator, he will have no difliculty in varying the proportions above given to meet his requirements in dealing with other kinds of iron and in effecting the result at which he may aim.

In making steel by any of the above processes by means of my alloy I use any proportion thereof which is suitable to the class of metal required, as will be well understood by an experienced operator. In practice I find that such proportion may be varied up to sixteen per cent. of the iron to be converted. If ahigher grade of steel be requ red, it can be obtained by adding the requisite amount of carbon to the alloy in the case of the crucible in the form of wood charcoal, and in the ease of the Bessemer or openhearth processes in the shape of pig-iron, as hereinafter described.

In using my alloy with a Bessemer converter in the case of a charge of ten tons of pig-iron I proceed as follows: The iron is first melted in the usual way in a cupola-furnace, or it can be taken from the blast-furnace direct when suitable kinds of iron are used, and then run into the converter. This is then subjected to the usual blow; but no lime, spiegeleisen or other substance should be introduced. While this is being done I take the proper proportion of alloysay, about ten hundred-weight to ten tons of hematite iron-and melt it in a cupola-furnace. In case a steel containing a larger proportion of carbon is required, I introduce pig-iron in sufficient quantities with the alloy into the cupola-furnace. At the termination of the first blow the molten alloy is run into the converter and the charge is then subjected to a further blow of about one-half minute, so as to thoroughly mix the alloy with the charge. No further mixing is required; but the converter should then be tilted and the contents poured into the ladle and thence into the ingot-molds.

My alloy can further be used to improve and strengthen iron castings.

In making iron castings by my process I have used about onethird of the total casting of alloy, one-third of scrap-iron, and one-third of pig-iron; but the proportion of alloy employed may be reduced, according to requirements, as an experienced operator will readily understand.

Though claiming the above proportional do not confine myself to them, as they may be varied according to the nature and quality of the castings required and the character of the metal used.

In treating iron by my process, in order to purify it and improve its quality the ingredients or alloy should be placed in the puddling-furnaee while the iron is in the molten condition and before it comes to nature.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be carried out or performed, I desire to state that I am aware that attempts have before been made toimprove the manufacture of iron and steel by the use of some of the ingredients hereinbefore mentioned; but

hat I believe to be new and original, and therefore claim, is-

1. A compound for use in the manufacture of iron and steel, consisting of carbonate and phosphate of calcium, black' oxide of manga nese, tannic acid or tannin, vegetable soot, and animal charcoal or bone-black, taken in substantially the proportions stated.

2. A compound for use in the manufacture of steel and iron, consisting of carbonate and phosphate of calcium, black oxide of manganese, tannic acid or tannin, vegetable soot, animal charcoal or bone-black, and tar, taken in substantially the proportions stated.

3. The process of forming an alloy for use in the manufacture of steel and iron, consistingin combining with pig-iron carbonate and phosphate of calcium, black oxide of manganese, tannic acid or tannin, vegetable soot, animal charcoal, and tar, in substantially the 15 proportions stated.

JAMES MAOKINTIRE.

Witnesses:

G. F. WARREN,

Notary Public, London. JOSEPH LAKE,

17 Gracechurch Street, London. 

